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authorJosef Bacik <josef@redhat.com>2011-04-13 15:15:59 -0400
committerJosef Bacik <josef@redhat.com>2011-05-23 13:00:57 -0400
commit2a1eb4614d984d5cd4c928784e9afcf5c07f93be (patch)
tree892b123c194e490a2dc0bc5b45f641ac921e9d26
parent7a7eaa40a39bde4eefc91aadeb1ce3dc4e6a1252 (diff)
downloadop-kernel-dev-2a1eb4614d984d5cd4c928784e9afcf5c07f93be.zip
op-kernel-dev-2a1eb4614d984d5cd4c928784e9afcf5c07f93be.tar.gz
Btrfs: if we've already started a trans handle, use that one
We currently track trans handles in current->journal_info, but we don't actually use it. This patch fixes it. This will cover the case where we have multiple people starting transactions down the call chain. This keeps us from having to allocate a new handle and all of that, we just increase the use count of the current handle, save the old block_rsv, and return. I tested this with xfstests and it worked out fine. Thanks, Signed-off-by: Josef Bacik <josef@redhat.com>
-rw-r--r--fs/btrfs/transaction.c17
-rw-r--r--fs/btrfs/transaction.h2
2 files changed, 19 insertions, 0 deletions
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 70bfb26..46f4056 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -184,6 +184,15 @@ static struct btrfs_trans_handle *start_transaction(struct btrfs_root *root,
if (root->fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR)
return ERR_PTR(-EROFS);
+
+ if (current->journal_info) {
+ WARN_ON(type != TRANS_JOIN && type != TRANS_JOIN_NOLOCK);
+ h = current->journal_info;
+ h->use_count++;
+ h->orig_rsv = h->block_rsv;
+ h->block_rsv = NULL;
+ goto got_it;
+ }
again:
h = kmem_cache_alloc(btrfs_trans_handle_cachep, GFP_NOFS);
if (!h)
@@ -213,7 +222,9 @@ again:
h->block_group = 0;
h->bytes_reserved = 0;
h->delayed_ref_updates = 0;
+ h->use_count = 1;
h->block_rsv = NULL;
+ h->orig_rsv = NULL;
smp_mb();
if (cur_trans->blocked && may_wait_transaction(root, type)) {
@@ -241,6 +252,7 @@ again:
}
}
+got_it:
if (type != TRANS_JOIN_NOLOCK)
mutex_lock(&root->fs_info->trans_mutex);
record_root_in_trans(h, root);
@@ -428,6 +440,11 @@ static int __btrfs_end_transaction(struct btrfs_trans_handle *trans,
struct btrfs_fs_info *info = root->fs_info;
int count = 0;
+ if (--trans->use_count) {
+ trans->block_rsv = trans->orig_rsv;
+ return 0;
+ }
+
while (count < 4) {
unsigned long cur = trans->delayed_ref_updates;
trans->delayed_ref_updates = 0;
diff --git a/fs/btrfs/transaction.h b/fs/btrfs/transaction.h
index 1f573f0..154314f 100644
--- a/fs/btrfs/transaction.h
+++ b/fs/btrfs/transaction.h
@@ -47,11 +47,13 @@ struct btrfs_trans_handle {
u64 transid;
u64 block_group;
u64 bytes_reserved;
+ unsigned long use_count;
unsigned long blocks_reserved;
unsigned long blocks_used;
unsigned long delayed_ref_updates;
struct btrfs_transaction *transaction;
struct btrfs_block_rsv *block_rsv;
+ struct btrfs_block_rsv *orig_rsv;
};
struct btrfs_pending_snapshot {
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